CET B-RFWireless Electronic Hot Water Cylinder Thermostat

User & Installation Instructions

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Certification Mark

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x Installation 3-10Product overview 3Specifi cation 4Thermostat installation 5-7Sensor wiring 8Receiver installation 9Receiver wiring 10

Schematics 11-14Hard wired heating, 3-port 11Wireless heating, 2 x 2-port 12Hard wired heating, 2 x 2-port 13Wireless heating, 3-port 14

Commissioning 15-17

User Instructions 18-21What is a cylinder thermostat? 18-19Setting the temperature 20Display 20-21Battery replacement 21

3

Installation Instructions

Product overview

The CET B-RF is a battery powered cylinder thermostat which measures cylinder temperature using a strap-on temperature sensor. The sensor is fi tted to the cylinder wall and wired to the thermostat, which is normally located adjacent to the cylinder.

To avoid the need for wiring, the thermostat and boiler or zone valve communicate to each other using secure RF wireless communication. A receiver unit is mounted next to the boiler or control valve and responds to commands issued by the wireless thermostat.

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Specifi cation

Product specifi cation (Thermostat)

Power supply : 2 x AA/LR6/MN1500 alkaline batteries

Transmitter frequency: 433.92MHz

Transmitter range: 30 metres line of sight

Temperature range: 40 - 65°C

Max. temp of thermostat: 45°C

Design standard: EN60730-2-9 (EN300220 for RF)

Dimensions, mm: 85 wide x 86 high x 42 deep

Control pollution: Degree 2

Ball Hardness 75°C

Temperature accuracy ±1°C

RX receiver unit: see instructions packed with receiver

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1. The clamp on sensor should be mounted onto the cylinder wall at a height equivalent to ½ the height of the cylinder. Care should be taken to remove any insulation material from the cylinder and to ensure that the copper surface of the cylinder is clean. See diagram opposite for details.

This product should only be installed by a qualifi ed electrician or competent heating installer and should be in accordance with the current edition of the IEEE wiring regulations.

1/2 cylinder height

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2. Before attaching the sensor to the cylinder using the strap provided, connect a 2-core cable to the sensor to allow interconnection to the thermostat setting unit.

3. Apply the contact paste provided to the part of the sensor in contact with the cylinder and clamp the sensor to the cylinder wall.

A spacer piece is provided for use with cylinders that have thick insulation (see opposite).

4. Mount the thermostat wallplate on to a wall next to the cylinder. Connect the cable from the sensor to terminals 2 & 3 of the wallplate (see wiring diagram on page 8).

5. Now mount the thermostat setting unit onto the wallplate and secure using the two screws on the bottom of the wallplate.

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For insulation thicker than 25mm and up to 55mm thick, use the extra cover supplied as a spacer to ensure that the sensor is held infirm contact with the cylinder wall.

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Sens

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CS1 sensor

1 2 3

CET

Cable specifi cation: minimum cross section 0.5mm2

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Installation - RX Receiver unit

1. Mount the RX wallplate onto the wall - cable access must be from behind or below the wallplate.

Typical wiring diagrams, showing the interconnection between time controls and zone valves, are shown on pages 11-14.

NOTE: Earth connections are for customer use only.

2. The RX receiver may now be mounted onto the wallplate and secured using the two screws on the bottom of the wallplate.

! Important note: Please ensure that when positioning the thermostat setting unit that there are no large metal obstructions, ie cylinder or boiler case, sitting in between the thermostat and the RX receiver unit as these will block radio communication and prevent the thermostat from operating correctly.

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Receiver Wiring (RF only)

A B C 1 2 3 4 5 6

ELECTRONICS

COMZONE 1

COMZONE 2

ZONE 1ON

ZONE 1OFF

ZONE 2ON

ZONE 2OFF

ZONE 1ON

N L

1 2 3 4

ELECTRONICS

N LCOM ZONE

1 ONZONE1 OFF

RX1

RX2C

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Note 1) For mains voltage operated systems link terminal 2 to mains live supply. 2) Power supply to unit must not be switched by timeswitch.

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Hard Wired Heating with Wireless Hot Water Control, 3 Port Mid-Position Valve

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Wireless Heating and Hot Water Control, using 2 x 2 Port Valves

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Hard Wired Heating with Wireless Hot Water Control, 2 x 2 Port Valves

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Wireless Heating & Hot Water Control, with 3 Port Mid Position Valve

LNLN 2 3 4

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1HW OFF HW ONHTG OFF HTG ON

FP715 Programmer

RX2C Receiver -channel 1 paired to heatingchannel 2 paired to CETB-RF

3 Port Mid-position Valve

Boiler/Pump

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1 2 3 4 5 6

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Commissioning Instructions

If the thermostat and receiver have been supplied together in a combined pack the units have been paired in the factory and no commissioning is required (RX1 only).

Step 1 Ensure that the power to the RX1 is turned on and that the programmer is calling.

Step 2 CET B-RF Turn the thermostat dial so

the widest end of the setting line is lined up with the LCD display (see opposite).

Remove dial, press & hold LEARN button for 3 seconds (located under setting dial).

Do not replace the setting dial yet.

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LEARN

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Step 3 RX1 Press and hold buttons PROG and CH1 until green

LED light fl ashes once

Step 4 RX2C For RX2C repeat steps 2 and 3 for channel 2

Step 5 CET B-RF Replace the thermostat dial, ensuring the widest end

of the setting line is lined up with the LCD display.

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RX1

NOTE: Thermostat now transmits unique identity signal continuously for 5 mins.

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Test the controls in the normal way to ensure that boiler, pump and associated control valve(s) operate in the correct sequence.

Having tested the controls, the thermostat should be set to the required temperature. This can be read directly from the LCD display as the setting knob is moved.

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What is a cylinder thermostat?... an explanation for householders

A cylinder thermostat switches on and off the heat supply from the boiler to the hot-water cylinder. It works by sensing the temperature of the water inside the cylinder, switching on the water heating when the temperature falls below the thermostat setting, and switching it off once this set temperature has been reached.Turning a cylinder thermostat to a higher setting will not make the water heat up any faster. How quickly the water heats up depends on the design of the heating system, for example, the

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size of boiler and the heat exchanger inside the cylinder.The water heating will not work if a time switch or programmer has switched it off . And the cylinder thermostat will not always switch the boiler off , because the boiler sometimes needs to heat the radiators.Cylinder thermostats are usually fi tted between one quarter and one third of the way up the cylinder. The cylinder thermostat will have a temperature scale marked on it, and it should be set at between 60°C and 65°C, then left to do its job. This temperature is high enough to kill off harmful bacteria in the water, but raising the temperature of the stored hot water any higher will result in wasted energy and increase the risk of scalding.If you have a boiler control thermostat, it should always be set to a higher temperature than that of the cylinder thermostat. In most boilers, a single boiler thermostat controls the temperature of water sent to both the cylinder and radiators, although in some there are two separate boiler thermostats.

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Setting the temperature

To alter the temperature that the thermostat controls at, simply turn the setting dial on the thermostat. As the setting dial is moved the small LCD display will show the selected temperature.

Please Note: In order to reduce the risk of Legionella infection, it is recommended that water be stored at not less than 60°C.

Display

Once the required temperature is set, the LCD display will show the temperature of the water in the cylinder close to the position where the sensor is located.

User Instructions

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A small fl ame icon is lit in the display whenever the thermostat is calling for heat. Please note that the boiler will only run when both the thermostat and the time control are calling.

Battery replacement

Batteries will last in excess of two years. When batteries need to be changed a battery icon will fl ash in the display.

To change the batteries loosen the two screws on the base of the thermostat and lift thermostat off base plate. Batteries are located in the rear of the thermostat unit and should be replaced using two high quality AA size alkaline cells.

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For a large print version of these instructions please contact the

Marketing Services Department on 0845 121 7400.

Part No 25322v07 07/07

Danfoss Randall LtdAmpthill RoadBedfordMK42 9ERTel: 01234 364621Fax: 01234 219705

For problems relating to your heating controls ...

Visit our website:www.danfoss-randall.co.uk

Email our technical department: drl_technical@danfoss.com

Call our technical department 0845 121 7505

(8.45-5.15 Mon-Thurs, 8.45-4.45 Fri)